On 16 November 2017 at 22:14, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote: > On 16 November 2017 at 21:37, Sami Tolvanen <samitolvanen@xxxxxxxxxx> wrote: >> On Thu, Nov 16, 2017 at 04:34:03PM +0000, Ard Biesheuvel wrote: >>> You still have not explained to us how GOLD avoids the erratum. >> >> Sorry, I didn't realize you were asking that. If gold spots erratum >> sequences, looks like it creates stubs to break them up: >> >> https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gold/aarch64.cc#l8396 >> >> It also attempts to optimize the code by replacing adrps in these >> sequences with adr where possible, but otherwise doesn't appear to >> touch them: >> >> https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gold/aarch64.cc#l2053 >> > > OK, so my concern here is that this code probably only operates on > fully linked binaries, and not partially linked object files like > kernel modules. The same applies to ld.bfd, which is why we need to > use the large module *model* not module > instead of a code model that may emit adrp > instructions.. > > What is preventing us from using the large model with clang? I know it > uses movk/movz pairs rather than literals, but this shouldn't matter > for modules, given that we support static ELF relocations. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
